Tire loaders have been widely employed in connection with automated tire machinery such as tire curing presses. Over the years such tire loaders have had a variety of different structural features depending upon the operational parameters involved such as the type of press and the type of tire being loaded. Since the advent of radial tires an important concern has been the need for the tire loader to locate very accurately the tire at the center of the press. Many prior art tire loaders simply could not attain the desired degree of precision and/or required difficult and time consuming adjustments.
Some prior art tire loaders have employed a horizontally swinging loader arm on which a loader basket or chuck was carried for horizontal movement into and out of the press. Loader baskets or chucks have included a circumferential arrangement of radially movable shoes which were expanded to engage and hold the upper bead of the tire. Loader arms also have been movable vertically to pick up a tire held by the loader basket from say a loader or conveyor in front of the press and later to lower the tire in the press. For precision centering, not only must the loader shoes be concentric with the center axis of the loader basket but such center axis must be accurately located at the center of the mold cavity by the loader arm. This is generally true for other types of tire loaders as well.
One problem associated with known tire loaders has been the inability or difficulty in maintaining concentricity of the loader shoes with the center axis of the loader basket over the entire range of bead size adjustment. It is noted that most loaders are designed to service a number of different tire bead sizes. Another problem has been difficulty in obtaining and maintaining accurate alignmnt of the center axis of the loader basket with the center of the mold cavity particularly during vertical movement of the loader basket in the press as may be needed for controlled transfer of the tire to the press.